He never killed a single person. In a show that practically runs on a conveyor belt of gore and stylized trauma, Nathan Harris remains one of the most unsettling figures to ever cross Spencer Reid’s path.
Most Criminal Minds "unsubs" follow a predictable trajectory. They have a "stressor," they snap, they kill, and eventually, the BAU kicks down their door. But Nathan was different. He was a kid who could see his own monster in the mirror and was absolutely terrified of it.
Honestly, the Season 2 episode "Sex, Birth, Death" shouldn't work as well as it does. It’s nearly two decades old. Yet, if you browse any fan forum today, Nathan’s name still comes up in every "characters we wish returned" thread. Part of that is the writing, but a huge chunk of it is the late Anton Yelchin.
He gave Nathan this jagged, vibrating energy—a mix of high-intelligence and total psychological collapse.
Who Was Nathan Harris?
Nathan Harris wasn't your average guest star. He was a high school student who sought out Dr. Spencer Reid after attending one of Reid’s lectures on "anger excitation" and serial killers.
Think about that for a second. Most people go to those lectures to learn about the "bad guys." Nathan went to find a manual for himself. He was already experiencing the classic "MacDonald Triad" signs—specifically, he admitted to feeling a sense of peace while killing a bird and becoming sexually aroused by cadavers.
He knew he was a ticking time bomb.
What makes him unique in the Criminal Minds universe is his self-awareness. He didn't want to be a killer. He was begging for a "cure" for a pathology that, as Gideon coldly noted, doesn't really have one. It’s one of the few times the show admitted that some people are just wired differently, and no amount of "talking it out" can fix the chemical or neurological urge to cause pain.
The Tragedy of the "Almost" Unsub
In the episode, Nathan is a red herring. While the BAU is hunting a killer targeting sex workers (Ronald Weems), Nathan is off in the periphery, basically "auditioning" for the role of a monster.
He stalks the crime scenes. He writes graphic, violent fantasies that he tries to pass off as a Jack the Ripper graphic novel script. But when he finally gets a sex worker alone in a hotel room, he can't go through with it. His empathy—or perhaps just his sheer self-loathing—wins out over his urges.
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The scene ends with him attempting to take his own life rather than becoming the predator he knows he’s destined to be. It’s dark. It's messy. And it leaves a massive question mark over the character's future.
Why "Sex, Birth, Death" Feels Different
Most episodes of this show are procedural. You get the profile, you get the chase, you get the arrest.
But Nathan Harris forced the team—and us—to look at the "pre-criminal." If someone knows they are a sociopath or a sexual sadist before they commit a crime, what does society do with them?
- The Mother's Denial: Sarah Harris (played by Jayne Atkinson, who later became Section Chief Erin Strauss) represented the classic parental blind spot. She saw a troubled son; the BAU saw a predator in training.
- The Reid Connection: Reid saw a mirror image of himself in Nathan—the isolated, hyper-intelligent outcast. The difference was the "urges."
- The Moral Dilemma: When Reid saves Nathan’s life at the end, he asks Gideon if he just saved a future killer. Gideon’s response is hauntingly pragmatic: "Then we’ll catch him."
The Anton Yelchin Factor
You can't talk about Nathan Harris without talking about Anton Yelchin.
Before he was Chekov in Star Trek or the lead in Green Room, he was this skinny kid with huge eyes who could make you feel sorry for a guy who wanted to dismember people. Yelchin had this "kindness" in his face that made Nathan’s internal struggle feel authentic.
When Yelchin died in that freak accident in 2016, the door on Nathan Harris officially slammed shut. Fans had long hoped for a "Season 15" or Evolution return where a grown-up Nathan either became a consultant (like a mini-Hannibal Lecter) or finally succumbed to his darkness. Now, he remains frozen in time as a 15-year-old kid in a hospital bed.
Real-World Inspiration?
While many Criminal Minds unsubs are direct clones of real killers (like the Fox/BTK or George Foyet/The Zodiac), Nathan Harris is more of a psychological composite.
He represents the real-world struggle of people with paraphilic disorders who seek help before acting. There are actual organizations, like the "Prevention Project," that work with individuals who have "minor-attracted" or "violent-attracted" thoughts but haven't offended.
Nathan is the fictional face of that "pre-offender" crisis. The show doesn't give us a happy ending because, frankly, there isn't an easy one for someone with his specific wiring.
What Happened to Nathan?
Since he never returned, we’re left with "headcanon."
The show implies he was institutionalized. Given the severity of his suicidal ideation and his admitted sadistic fantasies, he likely spent years in a high-security psychiatric facility. Some fans like to think the BAU's intervention worked and he "aged out" of his impulses—though psychologists will tell you that true sexual sadism doesn't just "go away."
The most realistic (and depressing) theory? He probably stayed in the system, a "success story" only in the sense that he never actually made it into the FBI's database as a murderer.
How to Re-watch (and What to Look For)
If you’re going back to watch "Sex, Birth, Death" (Season 2, Episode 11), keep an eye on the background details.
- The Drawings: Look at the "Jack the Ripper" art Nathan is working on. It’s legitimately disturbing and wasn't just "prop filler"—it was meant to show his obsession with the process of killing.
- The Subway Scene: The lighting in the subway station where Nathan confronts Reid is intentionally designed to split their faces into shadow and light. It’s a classic "dual nature" visual trope.
- The Dialogue: Notice how often Nathan uses the word "we" when talking about killers. He already identifies as one of them, even though he hasn't done the work yet.
Take Action: If you’re a writer or a fan of character studies, use the Nathan Harris arc as a masterclass in "The Reluctant Villain." Watch how the episode builds tension not through what he does, but through the potential of what he might do. It’s a much harder story to tell than a standard "slasher" plot, and it’s exactly why we’re still talking about it today.